The present invention relates to an marine cable for a fiber optic waveguide with regenerator supply line, which has a central LWL-bundle-conductor wire that is surrounded by at least one stranded layer of high-tensile elements and by a watertight metal casing.
An LWL-bundle conductor, as known to those of skill in the art, is comprised of a sleeve in which several fiber optic waveguides extend longitudinally, wherein the sleeve is filled with a filler. The LWL-bundle conductor is known in the U.S. under the name "maxi-bundle.RTM.", which is a trademark of SIECOR.
Such an marine cable with regenerator supply is known from U.S. Pat. No. 4,156,104. The cable described therein contains optical transmission elements in its center, which are surrounded by a stranded bond of sheathing wires. The stranded bond, in turn, is enclosed by a thick metal casing. The exterior of the cable has a thick insulating layor, which consists of two different plastic layers.
The mentioned marine cable has the disadvantage that, in the long term, the outer plastic insulation becomes damaged from the effect of moisture, and that the plastic insulation cannot prevent mechanical damage to the cable.
In French patent application FR-A-2 547 066 corresponding to U.S. Pat. No. 4,671,611), an marine cable is described that has optical waveguides running through its core, which are surrounded by a common insulating plastic layer. This cable core is surrounded by a stranded bond of steel or aluminum wires. The stranded bond is contained by a welded copper sheath. On the outside, the cable has a plastic insulation.
This cable, known from the French application, has, on its exterior, only a very vulnerable plastic insulation. The danger exists, that the moisture can penetrate through to the copper sheath. Since the stranded bond touches the copper sheath, an insulation of the cable core, in this case, is no longer provided.
British patent application No. GB-A-2 189 071 describes a marine cable, whereby a compressible medium, for example foam or silicon, is added between the individual stranded bonds of the sheathing wires. The purpose of this is to prevent any harm to the cable when it is unrolled.
This cable is not provided with a protective metal sheath. This is necessary, however, especially to protect against penetrating moisture. Once the outer plastic layer of the cable has been damaged, the outer stranded bond of the sheathing wires is exposed to an ingression of water.
In British patent application No. GB-A-2 005 861, an marine cable is also described with integrated optical transmission elements. The essential disadvantage of the marine cable in this British application is that its thick plastic insulation on the outside is very vulnerable, and if any damage occurs, it no longer guarantees an insulation of the cable core.